In “classical” flute music, we articulate notes with the tongue quite often. In Irish music, there can sometimes be a bit of a debate about this, which seems to have evolved over time.
Some trad musicians will insist that there’s no need to tongue any notes. After all, bagpipes get all their sound (including anything you would consider to be an articulation) from the quick burst of air they get by squeezing the air out of the bag and into the chanter. After that, anything our ear perceives to be any type of articulation is typically done by means of ornamentation. If that works for bagpipes, why shouldn’t we do the same?
When there’s a situation where a classical player might instinctively tongue a note, a trad player might “throat” the note, which is a term that has floated around a bit, but it might be a bit of a misnomer. What some people refer to as “throating” is a type of tonguing. If you thinking about the “tu-ku” we use when double-tonguing, think of the “tu” as tonguing and the “ku” as “throating”. This “half double-tongue” articulation is sometimes used.
Of course, some players (and I suppose all players, sometimes) will initiate a note without any involvement from the tongue. To just start moving air without using the tongue at all might feel strange to a classical player, but it might fit nicely in a particular tune, so it’s worth a try.
In short, there’s no one answer to the question of tonguing. If you’re able to use tonguing, throating, and also completely leave out the tongue, all with equal ability, you’ll just have that many more tools in your toolbox. What’s most important is that you feel the tune, intrinsically, you’ll naturally apply whichever of these techniques works best. Trust yourself!